The following meanings for the abbreviations used in this specification apply:    Ack Acknowledgement    CCA Credit Control Answer    CCR Credit Control Request    eNB enhanced Node-B    E-UTRAN Evolved Universal Terrestrial Radio Access Network    HSS Home Subscriber Server    IP Internet Protocol    IP-CAN Internet Protocol Connectivity Access Network    MME Mobility Management Entity    OCS Online charging system    PCS Policy Control System    PCEF Policy and Charging Enforcement Function    PCRF Policy Charging and Rules Function    P-GW Packet Data Network (PDN)-Gateway    PDP Packet Data Protocol    RRC Radio Resource Control    S-GW Serving Gateway    UE User Equipment
Introduction of 3G and wide range of smart phones have substantially increased the number of PDP sessions in the network. However, the growth in the number of PDP context can't be attributed to increased network usage alone, since this is also dependent on the behaviour of the devices in the network. A current operator network analysis has indicated that a majority of the PDP context initiation is from the devices that may have unsuccessful PDP context creation. The reason could be that a subscriber may not be entitled for a certain service, as for example, due to the subscriber's low credit for such a service.
Some of the new generation phones, often referred to as smart phones, provide a mechanism to automatically keep retrying for PDP session establishments which might have failed in the first instance due to non-entitlement of the subscriber for a service. Such repeated re-trying to establish PDP sessions may create unnecessary signaling and increased load on network elements to handle session establishment procedures hampering network performance and efficiency.